Alien plants often form dense stand and are therefore more noticeable than animals. However, there are already around 150 established alien species present in Slovenia, of which many are invasive and are causing damage to biodiversity. Many species are present in freshwater due to introductions or fish from other continents and translocations between the Danube and Adriatic catchments which were done in the past. In the forest, the number of alien insects is increasing and these can have a significant impact on tree species and can lead to alteration of species composition and functioning of the forest ecosystem.
Below are some animal species for which we have already prepared descriptions (only in Slovenian) of some of the alien animals. Some are already present in Slovenia, others are listed on the alert list.
Observation list: Includes selected alien species, which are relatively widespread in Slovenia and recognised as invasive. Reporting these species is important for monitoring their spread, planning of management measures and awareness raising.
Alert list: Includes potentially invasive alien species, which are likely to arrive in or spread to Slovenia in the near future. Some of the alert list species are already present in Slovenia and locally forming larger populations, however with adequate measures, their further spread could still be prevented.